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Product Info

What is Comfortis?

Comfortis is the first FDA-approved, chewable beef-flavored tablet (derived from pork protein and hydrolyzed soy) that kills fleas and prevents flea infestations on dogs and cats for a full month. Comfortis for Dogs & Cats requires a prescription from your veterinarian.

For:

Dogs & Cats (14 weeks of age or older)

Benefits:

Starts killing fleas within 30 minutes

Lasts a full month

Kills fleas before they can lay eggs

Comes in a convenient chewable, beef-flavored tablet

Spinosad, the active ingredient in Comfortis, is environmentally friendly

How does Comfortis work?

The active ingredient in Comfortis (Spinosad) kills fleas by causing excitation of the insect's nervous system, leading to paralysis and rapid death.

Cautions:

Side effects may occur, including vomiting. If your pet is experiencing loss of appetite, lethargy, or any other difference in behavior, contact your veterinarian. The FDA has received reports of adverse reactions in dogs receiving the drug Comfortis (spinosad) concurrently with high, extra-label doses of ivermectin. Dogs receiving extra-label doses of ivermectin to treat non-responsive demodectic mange and other conditions have developed signs of ivermectin toxicity. Ivermectin is an ingredient found in heartworm preventatives such as Heartgard Plus, Heartgard, Iverhart Plus and Ivomec. In cats, the most common adverse reaction recorded in clinical trials was vomiting. Other adverse reactions were: lethargy, decreased appetite, weight loss, and diarrhea. Use with caution with concomitant extra-label use of ivermectin.

Brand Name:

Comfortis (Elanco)

Generic Name:

Spinosad

What is the most important information I should know about Comfortis?

Comfortis is a prescription medication FDA approved for use in dogs and puppies and cats and kittens 14 weeks of age or older to kill fleas and prevent flea infestations for one month. Comfortis is available in a Pink box for dogs 5 to 10 lbs and cats 4-6 lbs (140 mg), Orange box for dogs 10.1 to 20 lbs and cats 6.1-12 lbs (270 mg), Green box for dogs 20.1 to 40 lbs and cats 12.1-24 (560 mg), Blue box for dogs 40.1 to 60 lbs (810 mg), and Brown box for dogs 60.1 to 120 lbs (1620 mg). Please note: Cats over 24 lbs should be administered the appropriate combination of tablets.

What should I discuss with my veterinarian before giving Comfortis to my pet?

Tell your veterinarian if you are planning on breeding your pet. Tell your veterinarian if your dog or cat has a history of seizures (epilepsy).

How should Comfortis be given?

Give Comfortis chewable tablets with food. Give Comfortis chewable tablets once a month. Comfortis chewable tablets may be chewed, offered in food, or administered like other tablet medications. If vomiting occurs within 1 hour of administration, redose the pet with another full dose. Store Comfortis at room temperature (68-77 F)

What are the potential side effects of Comfortis?

Side effects that may occur include vomiting. If vomiting occurs within one hour of administration, redose with another full dose. Other side effects may occur. Continue giving Comfortis chewable tablets and talk to your veterinarian if your pet experiences decreased appetite, lethargy or decreased activity, diarrhea, cough, increased thirst, vocalization, increased appetite, redness of the skin, hyperactivity and excessive salivation. Talk to your veterinarian about any side effect that seems unusual or especially bothersome to the pet.

What happens if I miss giving a dose of Comfortis?

Give the missed dose as soon as you remember and resume a monthly dosing schedule.

What happens if I overdose my pet on Comfortis?

Contact your veterinarian immediately.

What should I avoid while giving Comfortis?

Your pet may maintain normal activities and interactions while being given Comfortis. The safe use of Comfortis in breeding, pregnant, or lactating cats and dogs has not been evaluated.

What other drugs will affect Comfortis?

Talk to your veterinarian before giving any prescription or over the counter medications.

How to Use

Comfortis Directions:

Comfortis is a prescription medication used in dogs and cats to kill fleas and prevent flea infestations for 1 month.

Comfortis chewable tablets are beef flavored.

Comfortis can be given to dogs at least 14 weeks of age, weighing at least 5 lbs, and cats 14 weeks of age, weighing at least 4 lbs.

Tip:

If vomiting occurs within 1 hour of administration, redose the pet with another tablet.

Comfortis Dosage for Dogs:

Dogs/Puppies (14 weeks of age or older):

Weight

Dosage

5-10 lbs (Pink Box)

Give one 140 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications

10.1-20 lbs (Orange Box)

Give one 270 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications

20.1-40 lbs (Green Box)

Give one 560 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications

40.1-60 lbs (Blue Box)

Give one 810 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications

60.1-120 lbs (Brown Box)

Give one 1620 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications

Over 120 lbs

Give the appropriate combination of tablets

Comfortis Dosage for Cats:

Cats/Kittens (14 weeks of age or older):

Weight

Dosage

4-6 lbs (Pink Box)

Give one 140 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications

6.1-12 lbs (Orange Box)

Give one 270 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications

12.1-24* lbs (Green Box)

Give one 560 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications

Rated 5 out of
5 by
Drdaves kids from
The most effective method to fight fleas.I tried Comfortis 3 years ago after watching all the topical treatments (Advantage etc) fail miserably. The dogs stay pest-free even in Hot weather. One tip - crush the tablets into powder, then mix it into something that has a good odor. Otherwise it can be a challenge to get the pills into your puppy.

Date published: 2017-12-25

Rated 5 out of
5 by
Sandyf59 from
Best flea treatment I have ever used.I have been using Comfortis on my dogs for a couple of years now and have not had any flea issues at all. The dogs do not have any side effects.

Date published: 2017-12-19

Rated 5 out of
5 by
KennyG from
Fleas don't stand a chance!Comfortis works extremely well and me and my little Shnauzer couldn't be happier. Within an hour of giving the dose, the fleas (let me say there were a bunch of 'em) were all gone and they haven't visited her since. Highly recommended product.

Date published: 2017-12-12

Rated 5 out of
5 by
Dory from
Effective If Swallowed :-)Comfortis comes in pill form. You can hide it in a piece of cheese or meat only if your dog has no sense of smell. My dogs spit the pills out everytime. So I have to use the "shove the pill down the throat" method. This Is fine with my little terrier, but my large mix-breed is another story. The pill for over 50lb dogs is huge (round & flat) and very hard to get down. So, I bought the cheaper Comfortis for my small dog to save money and bought a more expensive chewable flea preventive for my large dog. Although the pills can be difficult to administer, they are very effective.

Date published: 2017-12-08

Rated 5 out of
5 by
Yankee53 from
Amazingly effective!Over the years we’ve had 3 dogs and 4 cats. Never a problem with fleas. For the first time ever, this year we had a flea problem. Normal topicals were’t working Flea baths didn’t work. At the vet’s recommendation we tried Comfortis. I thought the claims made for this product were a bit optimistic. I’m accustomed to being consistently disappointed by overhyped products. Comfortis did exactly what it claimed it would do. Within an hour of giving Comfortis to our cat and dog, dead or dying fleas were literally falling off both animals. With that and some thorough cleaning followed bythe application of diatomaceous earth around the house, the flea issue has disappeared. I’ll add that the cat did vomit but not until 3 hours after being given Comfortis. The dog had no adverse reaction. Extremely effective.

Date published: 2017-12-06

Rated 5 out of
5 by
spike from
Our vet put my dog on Comfortis because she would end up biting the fur off her tail. It worked so well & we hadn't had to worry about fleas. My husband broke his foot & can't drive so we were without transportation for awhile. I ordered a 6 month supply form PetMeds & it was delivered to us quickly. We will continue to buy from PetMeds because not only was it fast delivery of this great product but, the price was cheaper than it was at our vets.

Date published: 2017-11-21

Rated 5 out of
5 by
Animal love from
FleasI was so hesitant to give my two cats and dog oral pesticide to kill the fleas. I tried the natural method first which actually did help but not resolve problem. Within hours dead fleas were falling off my animals. The product works great. My animals did well although I believe my 14 yr old cat seemed to have a fever for a day. I could tell he had a reaction but recovered well. It was torture to see them itch and scratch constantly. I do not regret giving in to the chemical approach.

Date published: 2017-11-18

Rated 5 out of
5 by
Nalaberry from
Easy to use, works fastI purchased this product from our Vet. After our 6 month supply ran out I wanted to purchase another 6 month supply. The Receptionist told me it would cost me an additional $50- because my dog weighed 2 pounds more, which was still way less than 20 pounds. When I questioned this, she said the Vet will return to the office next week, I could ask him why. My co-worker encouraged me to go through PetMed Express. I’m so happy I did! I saved $50- plus dollars, service was fast, doggie is very happy! I’ll continue to use your services, thank you so much.

How many months supply do you distribute

Thank you for your question. We offer Comfortis as a 6 pack (6 month supply) or a 12 pack
( 12 month supply).

Answered by: Crystal PetMed Pro

Date published: 2017-12-07

Will medicine cause diarrhea

Asked by: Jess

Thank you for your question. Diarrhea is a potential side effect of the medication.

Answered by: Crystal PetMed Pro

Date published: 2017-11-26

Does Comfottis help with ticks?

Asked by: Jeff

Comfortis kills fleas and prevents flea infestations on dogs and cats. It does not protect pets from ticks.

Answered by: Lisa M

Date published: 2017-11-27

What does the cat flea pill of Comfortis look like? My vet gave my cat 1 flea pill and it looked like a small pill. She sent me home with two more bigger pills of Comfortis. I'm worried I went home with the dog flea pills.

Asked by: maddyquilt

Actually, it is the same tablet used in both dogs and cats. The dose is different and cats actually take a higher dose than dogs. The smaller tablet you saw your vet give may have been Capstar, which is an excellent flea control but only lasts for 24 hours. The weight range for each species is written on the back of the individual tablet package so double check that to make sure you have the correct strength tablet for your cat.

Answered by: SuzyCVT

Date published: 2017-09-22

My cat is not eating this chewable tablet. Is it safe to crush it up and sprinkle on food? I broke it up in smaller pieces and it's been in his bowl for 2 days now.

Asked by: Beanie

It is ok to crush up the medication. Try giving it to your pet with a small amount of wet food so your pet will consume the entire dose at once. If your pet still doesn't eat it after that attempt please speak with your veterinarian regarding using an alternative medication that your pet will ingest or that can be applied topically.

Answered by: Lilli Pharmacist

Date published: 2017-09-28

Do I need a vets prescription to order?

Asked by: Viv22

From some other answers, I have learned that Comfortis is by prescription only.

Answered by: Connie 59

Date published: 2017-12-15

One month ago I gave my dog (60 lbs) a dose of Sargents flea oil along his back and there's still living fleas. I bough a tablet of Spinosad Comfortis from vet can I give tablet today? I forgot to tell vet the above?